The present invention relates to avionics displays, for rotorcraft such as helicopters and in particular to a compass display that provides improved depiction of surrounding obstacles better corresponding with the multiple degrees of freedom of rotorcraft.
In an aircraft, such as a rotorcraft, a compass is displayed to aid in navigation. Such instruments are now entirely digital and are displayed on screens of computers. In recent years, it has become common to display a moving map beneath the compass (“map view”). The center of the compass's position on the map represents the location of the aircraft and is usually indicated by an aircraft-shaped icon.
Recently, the map view has been enhanced to provide colored contours depicting the relative height of the surrounding terrain and symbols denoting ground supported structures such as towers. These contours and symbols aid the pilot in avoiding areas where the aircraft would collide with the terrain or structures.
The color-coded contours and symbols, while representing a height dimension of the terrain and structures, still provide depiction that is essentially two-dimensional. Although relative altitude of terrain and structures is indicated, no sense of three-dimensional space is conveyed.